Choose the correct statements from the following.
A \( \mathrm{Mn_2O_7} \) is an oil at room temperature
B \( \mathrm{V_2O_4} \) reacts with acid to give \( \mathrm{VO_2^{2+}} \)
C \( \mathrm{CrO} \) is a basic oxide
D \( \mathrm{V_2O_5} \) does not react with acid
Choose the correct answer from the options given below:
